Very low Vit D results in deranged calcium metabolism. Symptoms of numbness and tingling around the mouth is a cardinal sign of this.

So I would get that Vit D tested, and if low get on D3 right away.
The D doctors are still prescribing does not work well, and is called D2. So get tested and come back here with the results.

Also get a B12 test while you are there. Doctors will call very low B12 normal still, because the lab ranges haven't reflected changes in therapy. You should be at 400 or above, in US units.

These are the most common culprits to start investigating.

Another thing often very low in Americans is magnesium. 70% have shown in studies to be a eating magnesium deficient diet.
Here is my magnesium thread:
http://neurotalk.psychcentral.com/thread1138.html
magnesium OXIDE is common in most supplements and is not absorbed and does not help. My thread explains that.

This is a starting point. You have to start looking at your lifestyle and diet and be a detective to see if you can find something that triggered you and set off the PN.
Our subforum above, has posts to help you identify triggers.